Research scientist James Pitts died in his sleep on Thursday in his Irvine home, according to his wife and fellow UC Irvine professor Barbara Finlayson-Pitts, leaving behind a legacy of enthusiasm in chemistry, along with lasting changes in government air pollution policies.

To his longtime colleagues and friends, Pitts, 93, was known for his body of work in photochemistry and atmospheric chemistry and his role as a mentor for young chemists in a educational career that spanned 60 years.

According to an interview with Bowling Green State University in 2007, Pitts was born in Salt Lake City on Jan. 10, 1921, to Esther and James N. Pitts, before moving to West Los Angeles six months later.

Pitts discovered his love of chemistry while attending Manual Arts High School in the 1930s, which would eventually lead him to attend UCLA several years later as he sought a degree in chemistry.

After graduating from UCLA with a bachelor’s degree in chemistry in 1945 and doctorate in chemistry in 1949, Pitts became a professor at UC Riverside in 1954 to focus on fundamental photochemistry – where he began his nationally renowned research on air pollution in Los Angeles County.

His work, which detailed the dangerous exhaust emissions of combustion vehicles that produced smog during the late 1960s through the 1980s, would lead to numerous awards from Congress, the California State Assembly, the South Coast Air Quality Management District, and the state air board and the Coalition for Clean Air.

Longtime colleague and friend UC Irvine Vice Chancellor for Research John Hemminger said Pitts was a pioneer of atmospheric chemistry and photochemistry research, and the books he co-authored were akin to Bibles in the scientific community because his research was unique.

“He really educated a whole generation of scientists … He was an inspiration for lots of people,” Hemminger said. “My own personal directions of research have been inspired by Jim.”

UC Irvine chemistry professor Don Blake shared Hemminger’s view of Pitts, calling him a “pillar” in the scientific community for the work he did in ensuring clean air in California.

“We in Southern California owe him a debt of gratitude,” Blake said about the news of his friend’s death.

Blake said that Pitts’ influence is still prevalent in international discussions, since Hajime Akimoto, a retired Japanese professor and former post-doctorate student of Pitts, referenced Pitts’ clean air advocacy and its effects on government policies during a meeting of scientists in Hong Kong in January.

Mary Nichols, chairwoman of the California Air Resources Board, said that while Pitts’ work made major changes in the automotive industry, the greatest accomplishments Pitts left behind are the countless students he instructed and inspired in his years as an educator. “He trained generations of important scientists that came after him,” Nichols said. “In the world of science, that’s probably the greatest legacy one can leave.”

Pitts is survived by his second wife, Finlayson-Pitts, and three daughters from a previous marriage, Linda Lee, Christie Hoffman and Beckie St. George.